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Re: Do the following examples generate any triples?

From: Mark Birbeck <mark.birbeck@formsPlayer.com>
Date: Wed, 9 Jan 2008 10:33:27 +0000
Message-ID: <a707f8300801090233g44cac2e1raa2b3ad94487fab0@mail.gmail.com>
To: "Ivan Herman" <ivan@w3.org>
Cc: "Manu Sporny" <msporny@digitalbazaar.com>, RDFa <public-rdf-in-xhtml-tf@w3.org>

Hi Ivan,

On 09/01/2008, Ivan Herman <ivan@w3.org> wrote:
> Hi Manu,
>
> thanks for this, good questions. Let me take a stab at it....
>
> Manu Sporny wrote:
> > Hi Mark,
> >
> > Just to understand when certain triples are generated, it is my
> > understanding that all of the examples below should not generate any
> > triples, please verify:
> >
> > -----------------------------------------------------------------
> > <div resource="#me" rel="foaf:knows">
> >    <span resource="#ben">
> > </div>
> > -----------------------------------------------------------------
> >
>
> In all models
>
> <> foaf:knows <#me> .
>
> is generated if there is an implicit @about="" on the <body> element.
> But I am not sure that is the case, in which case that triple is not
> generated either (sorry Ben, we seem to disagree on that).

Ok...we need to check this. I think we say that the document URI
itself is the default for @about (which may be set by <base>), but
we'll need to double-check. But since we have agreed that this is what
we _want_, let's just assume for now that this _is_ the triple
generated.


> I first believed that in the model of Mark the
>
> <#me> foaf:knows <#ben> .
>
> is also generated regardless of whether the previous triple is
> generated. I then had to re-read the syntax document to find out, via
> the processing steps, that this is not so. (@rel has a higher priority
> in setting [new subject], ie, it will be set to null, and that is not
> send down to <span>)
>
> Which by itself is also significant (thanks, Manu!): if there is an
> uncertainty on this for us, too, this shows the extra complexity induced
> by the usage of @resource (sorry Mark:-)...

I'm not sure if it's completely logical to say that a proof of some
kind of extra complexity in the rules is that you had to read them!
But then I'm no mathematician. ;)


> > -----------------------------------------------------------------
> > <div href="#me" rel="foaf:knows">
> >    <span href="#ben">
> > </div>
> > -----------------------------------------------------------------
> >
>
> The behaviour should be _exactly_ like the one above.

Yes.


> > -----------------------------------------------------------------
> > <div href="#me">
> >    <span rel="foaf:knows" href="#ben">
> > </div>
> > -----------------------------------------------------------------
> >
>
> In the model of Mark @href sets the [new subject] in <div>, which is
> then turned into [current subject] that is sent down to <span>. Ie, the
>
> <#me> foaf:knows <#ben> .
>
> will be generated.

Yes. Ben seems ok with this. Are you, Ivan?


> > -----------------------------------------------------------------
> > <div resource="#me" rel="foaf:knows">
> >    <div resource="#ben">
> >       <a rel="foaf:knows" href="#mark">Mark</a>
> >    </div>
> > </div>
> > -----------------------------------------------------------------
> >
> > -- manu
> >
>
> <#me> foaf:knows <#ben> .
>
> will be generated for the same reason.

Not in my model...no. There is actually no connection between the
outer statement and the inner one. It could just as easily be written:

  <div resource="#me" rel="foaf:knows">
  </div>

  <div resource="#ben">
    <a rel="foaf:knows" href="#mark">Mark</a>
  </div>

The first statement gives:

  <> foaf:knows <#me> .

as usual, and the second gives:

  <#ben> foaf:knows <#mark> .

Ben indicated that he is happy with the second statements generating
said triples; are you?

Regards,

Mark

-- 
  Mark Birbeck, formsPlayer

  mark.birbeck@formsPlayer.com | +44 (0) 20 7689 9232
  http://www.formsPlayer.com | http://internet-apps.blogspot.com

  standards. innovation.
Received on Wednesday, 9 January 2008 10:33:31 GMT

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